对于雄性为异配性别的物种来说,一些座位上的等位基因频率在雌性和雄性中是不一样的:假定

题型:问答题

问题:

对于雄性为异配性别的物种来说,一些座位上的等位基因频率在雌性和雄性中是不一样的:假定A基因频率在雄性中是0.8,在雌性中是0.2,则这一频率在以后的世代中会怎样变化设计一个概括性的表达法,描述第n代后的雄性p和雌性P值。假定最初的值分别为p0和P0

考点:普通考研07理学群体遗传与进化(四)
题型:问答题

肝细胞的功能,除外()。

A.合成胆汁

B.合成血浆蛋白

C.生物转化

D.解毒功能

E.清除抗原

题型:问答题

男,30岁,因受凉后高热,寒战,咳嗽,咳痰2天。查体:体温38.5℃,右上肺语颤增强、呼吸音增粗,有湿性啰音。血常规:WBC14×10/L,N0.8,L0.2。下列哪项诊断可能性最大()

A.上呼吸道感染

B.急性支气管炎

C.肺结核

D.急性肺脓肿

E.右上肺肺炎

题型:问答题

异戊二烯经臭氧化,在锌存在下水解,可得到哪一种产物()

A.HCHO+OHCCH2CHO

B.HCHO+HOOCCH2COOH

C.HCHO+CH3COCHO

D.CH3COCHO+CO2+H2O

题型:问答题

企业文化的共同性基础是()

A.地域文化

B.商业文化

C.本土文化

D.民族文化

题型:问答题

Science is a dominant theme in our culture. Since it touches almost every facet of our life, educated people need at least some acquaintance with its structure and operation. They should also have an understanding of the subculture in which scientists live and the kinds of people they are. An understanding of general characteristics of science as well as specific scientific concepts is easier to attain if one knows something about the things that excite and frustrate the scientist.
This book is written for the intelligent student or lay person whose acquaintance with science is superficial, for the person who has been presented with science as a musty storehouse of dried facts, for the person who sees the chief objective of science as the production of gadgets, and for the person who views the scientists as some sort of magician. The book can be used to supplement a course in any science, to accompany any course that attempts to give an understanding of the modern work, or--independently of any course --simply to provide a better understanding of science. We hope this book will lead readers to a broader perspective on scientific attitudes and a more realistic view of what science is, who scientists are, and what they do. It will give them an awareness and understanding of the relationship between science and our culture and an appreciation of the roles science may play in our culture. In addition, readers may learn to appreciate the relationship between scientific views and some of the values and philosophies that are pervasive in our culture.
We have tried to present in this book an accurate and up-to-date picture of the scientific community and the people who populate it. That population has in recent years come to comprise more and more women. This increasing role of women in the scientific subculture is not a unique incident but, rather, part of the trend evident in all segments of society as more women enter traditionally male-dominated fields and make significant contributions. In discussing these changes and contribution, however, we are faced with a language that is implicitly sexist, one that uses male nouns or pronouns in referring to unspecified individuals. To offset this built-in bias, we have adopted the policy of using plural nouns and pronouns whenever possible and, when absolutely necessary, alternating he and she. This policy is far from being ideal, but it is at least an acknowledgment of the inadequacy of our language in treating half of the human race equally.
We have also tried to make the book entertaining as well as informative. Our approach is usually informal. We feel, as do many other scientists, that we shouldn’t take ourselves too seriously. As the reader may observe, we see science as a delightful pastime rather than as a grim and dreary way to earn a living.

This passage most probably is ______.

A. a book review



B. the preface of a book
C. the postscript of a book

D. the concluding part of a book

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